The invention relates to implantable medical devices and, more particularly, to component assemblies and device assembly processes for manufacture of implantable medical devices.
Implantable medical devices typically include a housing that encloses a variety of internal components, and protects them from the implanted environment. Within the human body, for example, the housing must be sealed to prevent the introduction of fluids or moisture. In many cases, however, the implantable medical device includes external components that extend outside of the housing and communicate with the internal components.
One example is an implantable cardioverter/defibrillator (ICD), which includes an internal battery, a charging capacitor, and electronic circuitry. The electronic circuitry ordinarily is coupled to pacing and diagnostic leads that extend outside of the device housing for positioning within or near the heart. To protect internal components while permitting electrical connections with external components, the ICD must include a feedthrough assembly that preserves the environmental integrity of the device housing.
In addition to environmental protection, volume and space efficiency is extremely important in an implantable medical device. In general, it is desirable to make the implantable medical device as small as possible, e.g., for patient comfort and surgical ease. Unfortunately, reduced size can create performance issues. As an example, battery longevity is, in part, a function of battery size. As additional functions are added to an implantable medical device, the size of other internal components can increase. Consequently, space and volume efficiency within the device housing is essential in maintaining performance while permitting incorporation of additional features.
Manufacturability is another concern in the design of implantable medical devices. Many steps in the manufacture and assembly of implantable medical devices still require the careful attention, skill, and time of trained manufacturing personnel. Efforts to simplify or reduce the complexity, cost, and time of the manufacturing and assembly process can directly impact the cost of the implantable medical device for patients. Accordingly, more simple and cost-effective device assembly processes for implantable medical devices are desirable.
In general, the invention is directed to an implantable medical device assembly having a more space-efficient housing and components, as well as processes for assembly of the implantable medical device with reduced assembly cost and less complexity. In this manner, the invention is capable of promoting overall reductions in the cost of an implantable medical device, while maintaining performance.
The implantable medical device may incorporate a battery, capacitor, circuit assembly, and interconnect assembly with respective electrical terminals arranged in a generally parallel configuration. This configuration permits the use of automated electronic module assembly techniques such as parallel gap or ribbon bond welding to electrically connect the terminals. A feedthrough assembly may present a set of terminals adjacent a corresponding set of additional terminals, also enabling the use of automated welding techniques.
In addition, in some embodiments, the battery and capacitor may be positioned side-by-side, with the circuit assembly sized for placement immediately above the battery. In this case, the combined thickness of the circuit assembly and the battery may be substantially equivalent to the thickness of the capacitor. The interconnect assembly then can be positioned over the circuit assembly and the capacitor. The resulting stacked arrangement is simple to assemble, and provides a reduced thickness profile that promotes space efficiency within the device housing.
In one embodiment, the invention provides an implantable medical device comprising a housing and a battery, capacitor and circuit assembly within the housing. The battery and capacitor have battery terminals and capacitor terminals, respectively, that form a first row of terminals. The circuit assembly has circuit terminals that form a second row of terminals adjacent the first row of terminals. The circuit terminals are electrically coupled to the battery terminals and the capacitor terminals.
In another embodiment, the invention provides a method for assembling an implantable medical device. The method comprises positioning a battery having battery terminals within a housing, positioning a capacitor having capacitor terminals within the housing such that the capacitor terminals form a first row of terminals with the battery terminals, and positioning a circuit assembly having circuit terminals within the housing. The circuit terminals form a second row of terminals. In addition, the circuit assembly is positioned such that the second row of terminals is positioned adjacent the first row of terminals. The method further includes electrically coupling the battery terminals and the capacitor terminals to the circuit terminals using an automated weld process.
In an added embodiment, the invention provides a feedthrough assembly for an implantable medical device. The feedthrough assembly includes an electrically insulative terminal block, and multiple contact elements mounted in an interior side of the insulative terminal block to form feedthrough terminals. First channels formed in an exterior side of the insulative terminal block allow communication of conductive pins to the contact elements. Second channels are formed in the contact elements for receipt of the conductive pins. Multiple electrically conductive pins are threaded through the first and second channels and fixed in place to electrically couple the pins to the contact elements.
In a further embodiment, the invention provides a capacitor assembly for an implantable medical device. The capacitor assembly includes a housing, a capacitor positioned within the housing, and capacitor terminals coupled to respective electrodes of the capacitor. A terminal block assembly carries the capacitor terminals and extends outward from the housing. In particular, the terminal block positions the capacitor terminals for placement adjacent and in substantial linear alignment with battery terminals associated with a battery assembly provided in the implantable medical device.
In an added embodiment, the invention provides a battery assembly for an implantable medical device, the battery assembly comprising a housing, a battery positioned within the housing, battery terminals coupled to respective electrodes of the battery, and a terminal block assembly that carries the battery terminals and extends outward from the housing and positions the battery terminals for placement adjacent and in substantial linear alignment with capacitor terminals associated with a capacitor assembly.
The invention can provide a number of advantages, as mentioned above. For example, the arrangement of the various terminals associated with the battery, capacitor, circuit assembly, and interconnect assembly permits the use of automated part placement and welding techniques to quickly, efficiently, and reliably make the necessary electrical interconnections. With the incorporation of a terminal block assembly, a similar arrangement of terminals can be provided for automated interconnection between the feedthrough assembly and the circuit assembly.
In addition, the stacked configuration of the components and, in particular, the arrangement and size of the circuit assembly relative to the battery and capacitor promotes efficient use of space within the device housing. In this manner, battery size can be preserved despite the incorporation of additional components devoted to enhanced functionality or better performance. Thus, the invention is capable of contributing to overall cost and performance advantages in an implantable medical device.
The above summary of the invention is not intended to describe every embodiment of the invention. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.